Cu(II) incorporation in κ-(ET) 2Cu[N(CN) 2]Br

Abstract

Analyses of CuBr and CuN(CN) 2 used in the preparation of κ-(ET) 2Cu[N(CN) 2]Br reveal both magnetic (1–42 ppm) and nonmagnetic (1–5%) contaminants. Markedly different resistivity profiles are obtained for κ-(ET) 2[Cu[N(CN) 2]Br samples prepared from various Cu(I) sources; some profiles show little or no resistive hump near 100 K. Rotating disk voltammetry studies indicate that the E 1/2 values for ET and the Cu[N(CN) 2]Br anion are similar. Accordingly, considerable quantities of Cu(II) must be produced during the electrochemical synthesis of κ-(ET) 2Cu[N(CN) 2]Br. Whether Cu(II) that is generated in this manner is incorporated into κ-(ET) 2Cu[N(CN) 2]Br is under investigation.